blob: 8893c4a6195f06529e8475b2f3688eae5b13deb4 [file] [log] [blame]
// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build aix || darwin || dragonfly || freebsd || hurd || (js && wasm) || linux || netbsd || openbsd || solaris || windows || plan9
// +build aix darwin dragonfly freebsd hurd js,wasm linux netbsd openbsd solaris windows plan9
package runtime
func gogetenv(key string) string {
env := environ()
if env == nil {
throw("getenv before env init")
}
for _, s := range env {
if len(s) > len(key) && s[len(key)] == '=' && envKeyEqual(s[:len(key)], key) {
return s[len(key)+1:]
}
}
return ""
}
// envKeyEqual reports whether a == b, with ASCII-only case insensitivity
// on Windows. The two strings must have the same length.
func envKeyEqual(a, b string) bool {
if GOOS == "windows" { // case insensitive
for i := 0; i < len(a); i++ {
ca, cb := a[i], b[i]
if ca == cb || lowerASCII(ca) == lowerASCII(cb) {
continue
}
return false
}
return true
}
return a == b
}
func lowerASCII(c byte) byte {
if 'A' <= c && c <= 'Z' {
return c + ('a' - 'A')
}
return c
}